you're going up to a very hostile environment. do you think you are ready for that? >> i know i'm ready for that because i've been trained the last five years. >> reporter: baumgartner, a 43-year-old austrian and elite sky diver will rise before daybreak and be lifted by a helium balloon. the assent will take three hours. temperatures will fall as low as minus 70 degrees. once he jumps, baumgartner wearing a pressurized suit will be in free fall for five minutes. his top speed could hit 700 miles per hour. he'll become the first human in free fall to break the speed of sound. >> nobody can tell me what happens to the human body in free fall when you fly super sonic speed. >> reporter: joe kittinger has held the skydiving record since 1960 when the air force captain jumped from 19 miles up. kittinger now 84 is helping to train baumgartner to break his record. >> we have better suits and better equipment but the danger is still there. hasn't changed a bit. >> reporter: nasa and the u.s. air force will monitor baumgartner's jump to learn about high altitude limits on th